Defensive necessity is the deny of the theory of "defense to objects" and emphasis of key factors of "illegal violation", and is effective in solving the problem of defense to legal offense. There is no excuse in civil law, so defensive necessity is seen as the justifiable cause since introduced, though the understanding is not comprehensive. The status of defensive necessity should be determined by the measurement of legal interests. If the loss is less severe than danger, it is justified. If the loss is severer than danger, it should be seen as an ex-cuse. Defensive necessity is looser in qualification than necessity, milder than justifiable defense in urgency, and distinct in policy value. The qualification of defensive necessity is that, in a necessity on life, the victim is spe-cific, and lives protected are more than the number of victims.%防卫性紧急避险是“对物防卫”理论之否定和“不法侵害”要件之强调，在对合法危险源进行避险的问题上游刃有余。在民法中不存在免责事由，所以防卫性紧急避险自引入以来均被认为是违法阻却事由，然而这样的定位以偏概全。应当根据法益衡量的结果确定防卫性紧急避险的地位，在“损害小于危险”的情况下成立阻却违法的紧急避险，而对于非造成“明显失衡”损害的情形，仍存在成立阻却责任紧急避险的可能性。因此，防卫性紧急避险在限度上比紧急避险宽松，在紧迫性认定上比正当防卫温和，在制度价值上超然独立。在针对生命法益的紧急避险中，必须同时符合被牺牲者特定，且损害的生命在数量上不超过保护生命的条件，方能满足防卫性紧急避险的限度要求。
展开▼
